Apparatus for producing super heated fluids

ABSTRACT

The disclosure relates to an apparatus for producing super heated fluids by converting electromagnetic energy into thermal energy within the fluid. A coil of low dielectric tubing is placed in a microwave resonant chamber and extends from a fluid inlet to a vapor outlet. The fluid to be super heated passes through the coil and is vaporized directly by microwave energy. The invention is particularly applicable to a vapor powered vehicle that produces no environmental pollution.

United States Patent 1191 Long et al. [4 Dec. 11, 1973 [54] APPARATUSFOR PRODUCING SUPER 3,332,710 7/1967 Doty 285/368 HEATED FLUIDS2,202,494 5/1940 Jacocks 165/81 UX 3,577,322 5/1971 Nesbitt et al.219/1055 X 1 Inventors: Raymond g, 26323 ge 3,607,667 9/1971 Knapp etal.219/1055 x Rd., Damascus, Md. 20750; Ralph Boles 12005 Clandge PrimaryExaminerC. L. Albritton wheaton 20902 Assistant Examiner-Hugh D. Jaeger[22] Filed: Nov. 10, 1971 Att0rneyWilliam D. Hall et a1.

[21] Appl. No.: 197,422

[57] ABSTRACT 52 us. 01 219/1055, 122/6 A 165/81 The dislsure relates anapparatus Pmducing 180/67 super heated fluids by convertingelectromagnetic en- 511 1m. 01. H05b 9/06, B 60k 3/00 ergy thermalenergy within the fluid- A 158 Field 61 Search 180/67- 219/1055 dielewicin is Placed in a microwave 219/1051 285/365) 364 chamber and extendsfrom a fluid inlet to a vapor out- 287h29 3 let. The fluid to be superheated passes through the coil and is vaporized directly by microwaveenergy. [56] References Cited The invention is particularly applicableto a vapor powered vehicle that produces no environmental pol- UNITEDSTATES PATENTS lution 3,495,648 2/1970 Amadon 219/1055 3,277,870 10/1966Reale 122/6 A 7 Claims, 4 Drawing Figures j I I I I I l8 T W v I 7 4 ABACKGROUND OF THE INVENTION One of the primary drawbacks to presentvapor or steam driven automobiles is the warm-up time necessary tovaporize the liquid before the vehicle may be moved. While a variety ofvarious methods have been proposed for heating this fluid, none haveinvolved the successful application of microwave energy.

Microwave energy has been used in the past upon repeated occasions forheating solids and fluids. For example, U.S. Pat. No. 3,535,482, issuedto J. H. Kluck, on Oct. 20, 1970, illustrates a microwave source forrapidly heating a fluid to be pasturized, and then recooling it again.This reference discloses a method of heating fluids to temperaturesabove their boiling points while they are under pressure to destroybacteria and the like. It envisions that the fluid would be subjected tothe microwave heating for an exposure time in the order of 0.1 to 0.01of a second.

US. Pat. No. 2,978,562, issued to H. D. Fox, on Apr. 4, 1961,illustrates an instantaneous water heating system wherein the waterheater heats the fluid on demand, and does not maintain or store a largebody of heated water for domestic use. It discloses a spirally woundplastic tubing with a microwave source centered therein which isenergized when the water begins to flow.

None of the prior art references disclose or teach an apparatus forproviding super heated fluids for heating fluids at pressures andtemperatures far in excess of the normal temperature-pressurevaporization curves. These references do not disclose as their end orterminal product a super heated fluid in the vapor state. The superheated nature of the vapor has proved very advantageous in conveying themaximum amount of energy from the energy source to the vapor turbine orsteam engine. The super heated nature of the vapor, and the amount ofenergy required to generate the super heated vapor would destroy theconventional prior art apparatus if an attempt were made to generate thesuper heated vapor with it.

SUMMARY OF THE INVENTION It is therefore an object of this invention toprovide an apparatus which will utilize microwave energy to generatesuper heated vapor at high pressure levels. This apparatus will findparticular application in pollution free motor vehicles where theinstantaneous generation of vapor or steam is desirable.

It is another object of this invention to provide an apparatus that willwithstand the high pressures and temperatures at which it is intended tooperate. The apparatus envisions the use of a borosilicate tube which isprestressed in its coil form to normalize those stress loadings when thedevice is operating at its intended pressure and temperature levels.This coil is freely suspended within the microwave resonant chamber toprovide for expansion and contraction of coil as it is heated. Themicrowave generating source is removed from the resonating cabinet andconnected therewith by means of a wave guide to prevent the destructionof the magnetron which would normally occur if the magnetron wereexposed to theenergy levels that will be present in the resonatingcavity when the device is operating at its intended pressure andtemperature levels.

A wave guide means and deflector further assist in directing themicrowave energy to a specific region of the coil to ensure that thevapor leaving the coil is free from any suspended moisture or fluiddroplets.

Although the device is intended to operate in very high pressure levelsand very high temperature levels, it is quite apparent that the outputof the device is variable between 1 and 1,000 psig, and from 0 to 300 or400 F of super heat, beyond the normal temperaturepressure variationcurve.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagramatic cross sectionview of the apparatus for producing super heated vapor according to myinvention.

FIG. 2 is a chart illustrating the specific heat in BTUs per pound perdegree Fahrenheit for water vapor at five levels of constant pressure.

FIG. 3 is a cross sectional view of the glass to metal joint wherein theborosilicate glass tubing is attached to the fluid inlet and vapor inletof the resonant chamber.

FIG. 4 is a diagramatic plan view of a vehicle with a vapor engine, anda device for producing super heated vapor in accordance with thisinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 discloses the apparatusfor generating super heated vapor. While the description of thisapparatus and its operating temperatures and pressures will be for thegeneration of water vapor, it is to be understood that any suitablefluid may be used. Only the operating parameters would be changed.

The generating apparatus is contained within casing 11 and defines awater inlet 12 and a vapor outlet 13. The inlet and outlet are connectedby means of flanges l4 and 15 to a length of borosilicate tubing 16which is helically coiled and completely enclosed within casing 11.

Surrounding the borosilicate coil is a reflective layer 17 which isdesigned to reflect the microwave energy, and cause it to resonatewithin the chamber defined by reflective layer 17. An insulating andvibration absorbing layer 18 surround reflective layer 17 and providesnot only insulation for the extremely high temperatures at which thedevice is intended to operate, but also provides a shock absorbing ormovement absorbing means for dampening vibrations caused by suddenmovements of the generator when the generator is mounted in a motorvehicle. The borosilicate coil 16 is freely suspended between flanges 14and 15 and is not supported by any other means.

The coil 16 is prestressed when it is wound to normalize the stresseswhen operating at its intended temperature and pressure levels. Thus ifthe device were intended to operate at 750 psig and 700 F then the coilwould be stressed during its winding so that at those temperatures thestress loads induced in the coil would be completely normal.Borosilicate glass has been selected since at the present time there isno known plastic tubing that will operate at the pressure andtemperature ranges intended and not breakdown under microwaveenergization. It is important that any material selected for coil 16 beessentially transparent to microwave energy, and low dielectric glasstubing is essentially transparent.

The microwave energy used to heat the fluid passing from the water inlet12 to the vapor outlet 13 is generated by a magnetron tube 19 which issuitably connected to the resonant chamber by means of a wave guide 20.It is to be understood that any number of microwave generators may beemployed, but one example of such a generator is a magnetron tube suchas that i1- lustrated at 19 which operates in the range of 600 MHz.

The length of the wave guide 20, its interior dimensions, and thedimensions of the resonant chamber defined by reflective layer 17 aredetermined by the frequency of magnetron 19. It has been found necessaryto isolate the source of microwave energy from the resonant chambersince if it were placed within the chamber it would be very rapidlydestroyed by the amount of microwave energy present therein. Adeflecting means 21 is further provided within the wave guide 20 toprotect and isolate magnetron 19. This wave guide also tends to directthe primary waves of energy to the uppermost coils of the borosilicatetubing 16. This ensures that the fluid passing through coil 16 isvaporized when it leaves outlet 13. Any drops of moisture or suspendedliquid are instantly vaporized at the upper regions since those regionsreceive the primary burst of energy from the microwave generator.

As was pointed out previously, the device is capable of operating at anypressure and temperature level from to 300 or 400 F of super heat andfrom 1 to 1,000 psig. Since the net external work that may be performedin a vapor engine or steam engine is proportional to the amount of heatsupplied to the substance, and therefore the amount of increase in totalheat, it is desirable to operate the steam generator in the super heatregion. If heat is added at constant pressure, as in the subjectapplication, no net external work is done and all heat is used toincrease the enthalpy of the vapor. Thus the change in enthalpyrepresents the heat absorbed at constant pressure. Once the steam istransmitted to the vapor engine, be it turbine or piston type, thechange in enthalpy produced by the super heat can be converted to usefulwork by adiabitic expansion within the device.

The device is then intended to operate between the pressure andtemperature levels that provide saturated steam, and the pressure andtemperature levels which define the critical point for water vapor. Thecritical point is defined here as pressures higher than the criticalpressure, and temperatures higher than the critical temperature, whereinthe fluid or vapor exists as a single phase only, and the vapor pressurecurve is terminated in the critical point.

As can be noted in FIG. 2, the specific heat in BTUs per pound perdegree Fahrenheit necessary to excite the vapor for each additionaldegree of super heat drops after the vapor becomes saturated and movesinto its super heated state. FIG. 2 illustrates water vapor at 200, 400,600, 800, and 1,000 pounds per square inch. Each of the curvesrepresents the specific heat necessary to raise the vapor by thetemperature indicated on the abscissa of the graph.

The enthalpy, as measured in BTUs per pound for saturated steam is setforth below:

Absolute 400 1204.5 Pressures 00 1198.6 1000 1191.8 The enthalpy howeverfor super heated steam as measured in BTUs per pound is set forth below:

Enthalpy, BTU/lb. for Super Heated Steam Temperature F.

Since water vapor is readily compressible, and the total amount of vaporin pounds that may be carried in a given sized conduit between thegenerator and the vapor engine is substantially greater at 1,000 poundsper square inch than 400 pounds per square inch, it is quite apparentthat the amount of useful heat increases rather dramatically as theamount of super heat increases, even though the enthalpy for each poundof steam declines. I

In the subject invention, the borosilicate glass tubing is designed tooperate at these temperatures and pressures. These temperatures andpressures, and the microwave energy do present specific engineeringproblems in the instant application. FIG. 3 is a cross sectional view ofthe flange system 14 and 15 wherein the borosilicate tubing 16 issuspended between the water inlet and the steam outlet. The borosilicatetube 16 has defined on its end portion a flange 22 which mates with ametal flange 23 and metal tubing 24. This metal shielding prevents theescape of microwave energy to the exterior of the resonant chamber 11.The borosilicate glass flange 22 is completely surrounded with a packingmember 25 and directly abuts a gasket member 26. The packing material 25is retained by a slip ring 27 and a two part mating flange 28 which isbolted to the metal flange 23. The mating flange 28 and ring 27 providefor compression of the packing material 25, and holds the flange 22 indirect engagement with metallic flange 23. It also serves to compressgasket member 26. This elaborate packing mechanism is designed not onlyto prevent the escape of super heated steam at very high pressure, butis also designed to provide a resilient mount for the borosilicatetubing 16 and provide for expansion of the tubing 16 as it is heated bythe water vapor. As pointed out previously, the tubing 16 is completelysupported between the inlet 12 and the outlet 13 by means of the flangemembers illustrated in FIG. 3. It is completely free floating and thisis again intended to allow for expansion of the tubing at its intendedoperating level. The insulating and shock absorbing means 18 which isplaced between the reflective layer 17 and the outer casing 11 serves tosupport the tubing horizontally, and prevent any excess horizontalmotion when the device is placed in a motor vehicle.

FIG. 4 illustrates a motor vehicle equipped with a vapor or steam engine30 and conventional differential and axle means 31. The steam engine 30may be a steam turbine, or one of the many varieties of expansionchamber motors currently in use. Super heated steam is produced for thisvapor engine by means of the apparatus illustrated in FIG. 1 andindicated by the numeral 32 in FIG. 4. Conduit 33 provides a passage wayfor the super heated steam and conduit 34 provides an outlet for theexhaust steam. The exhaust steam is used in heat exchanger 35 to heatthe incoming water that passes from the water storage chamber 36 throughheat exchanger 35 to the super heated steam generator 32. Afterpreheating the water or other fluid, the steam is then exhausted throughconduit 37 into condensor 38 mounted at the front of the automobile.After being condensed back to its liquid form it is collected in theliquid storage tank 36 for reuse within the system via a pump 39. Aspointed out previously, steam and water vapor have been used forpurposes of illustration, although it is quite apparent that any otherliquid and vapor that would provide the desired temperature and heatcharacteristics could be used.

While specific means have been illustrated in specific examples andmentions given herein, it is to be understood that various modificationsof this system or the operation thereof would occur to one skilled inthe art. Accordingly it is understood that the present invention is notlimited to these illustrations and examples, but is to be limited onlyin accordance with the appended claims.

We claim:

1. Means for producing superheated vapor including a. means forgenerating microwave energy,

b. a microwave resonating chamber, said chamber having shielding meansto prevent the escape of microwave radiation, said chamber havingreflecting means mounted within said chamber, said chamber definingfluid inlet and vapor outlet means, the dimensions of the chamber beingmatched to the frequency of the means for generating microwave energy toprovide a resonant chamber for said energy,

c. a coil of low dielectric tubing mounted within said chamber, saidtubing connecting said fluid inlet and said vapor outlet means, and

d. wave guide means connecting said microwave generating means with saidresonant chamber to direct said microwave energy to the exterior of saidcoil, said energy directed towards the coil adjacent the vapor outlet.

2. Means for producing superheated vapor as claimed in claim 1 whereinsaid coil is formed of glass tubing, said tubing being prestressedduring the formation of said coil to allow unloading of said stress whensaid coil is subjected to its design temperature and pressure.

3. Means for producing superheated vapor as claimed in claim 1 whereinprotective means are inserted between said resonating chamber and saidmeans for generating microwave energy.

4. Means for producing super heated vapor as claimed in claim 1 whereinsaid coil is formed of borosilicate glass.

5. Means for producing super heated vapor as claimed in claim 4 whereinsaid coil is suspended within said resonant chamber and anchored only atsaid fluid inlet and vapor outlet.

6. Means for producing super heated vapor as claimed in claim 5 whereinsaid coil is mounted to said inlet and outlet by flanges defined oneither end of said coil, each of said flanges being abutted against asimilar metal flange, a retaining means for clamping said glass flangeto said metal flange with shock absorbing material completelysurrounding said glass flange.

7. Means for producing super heated vapor as claimed in claim 5 whereinsaid coil is suspended within said chamber and cushioned against anylateral movements by a shock absorbing means surrounding said coil.

1. Means for producing superheated vapor including a. means forgenerating microwave energy, b. a microwave resonating chamber, saidchamber having shielding means to prevent the escape of microwaveradiation, said chamber having reflecting means mounted within saidchamber, said chamber defining fluid inlet and vapor outlet means, thedimensions of the chamber being matched to the frequency of the meansfor generating microwave energy to provide a resonant chamber for saidenergy, c. a coil of low dielectric tubing mounted within said chamber,said tubing connecting said fluid inlet and said vapor outlet means, andd. wave guide means connecting said microwave generating means with saidresonant chamber to direct said microwave energy to the exterior of saidcoil, said energy directed towards the coil adjacent the vapor outlet.2. Means for producing superheated vapor as claimed in claim 1 whereinsaid coil is formed of glass tubing, said tubing being prestressedduring the formation of said coil to allow unloading of said stress whensaid coil is subjected to its design temperature and pressure.
 3. Meansfor producing superheated vapor as claimed in claim 1 wherein protectivemeans are inserted between said resonating chamber and said means forgenerating microwave energy.
 4. Means for producing super heated vaporas claimed in claim 1 wherein said coil is formed of borosilicate glass.5. Means for producing super heated vapor as claimed in claim 4 whereinsaid coil is suspended within said resonant chamber and anchored only atsaid fluid inlet and vapor outlet.
 6. Means for producing super heatedvapor as claimed in claim 5 wherein said coil is mounted to said inletand outlet by flanges defined on either end of said coil, each of saidflanges being abutted against a similar metal flange, a retaining meansfor clamping said glass flange to said metal flange with shock absorbingmaterial completely surrounding said glass flange.
 7. Means forproducing super heated vapor as claimed in claim 5 wherein said coil issuspended within said chamber and cushioned against any lateralmovements by a shock absorbing means surrounding said coil.